1. Field of the Invention
The present invention relates to a clip that is attachable to a subject member (e.g., a vehicle body). More particularly, the present invention relates to a clip that is attachable to the subject member by inserting an anchor portion thereof into an insertion hole formed in the subject member.
2. Description of Related Art
This type of clip is already known and is taught, for example, by Japanese Laid-Open Patent Publication No. 2002-81422. The clip includes an anchor portion (an engagement portion) that is inserted into an insertion hole formed in a subject member. The anchor portion has a plurality of flexible strips. When the anchor portion is pushed into the insertion hole, the anchor portion is inserted into the insertion hole while each of the flexible strips are flexed inwardly, so that a projected portion (a shouldered portion) of each of the flexible strips can engage a periphery of the insertion hole. Thus, the clip can be attached to the subject member.
Generally, as shown in FIG. 7, each of the flexible strips 52 of the anchor portion 50 is integrally connected to a support strip 53 of the anchor portion 50 only via a connecting portion 52a corresponding to a distal end of the anchor portion 50 (an anchor distal end side connecting portion 52a) and a connecting portion 52b corresponding to a proximal end of the anchor portion 50 (an anchor proximal end side connecting portion 52b). Further, the distal end of the anchor portion 50 has a cone shape such that the anchor portion 50 can be easily pushed into the insertion hole 22 of the subject member 20. Therefore, the anchor distal end side connecting portion 52a of each of the flexible strips 52 is thinner than the anchor proximal end side connecting portion 52b of each of the flexible strips 52. That is, the anchor distal end side connecting portion 52a has a junction area (a second moment of area) smaller than the anchor proximal end side connecting portion 52b. 
According to the clip in which the anchor distal end side connecting portion 52a is thinner than the proximal end side connecting portion 52b, as shown by broken lines in FIG. 7, the anchor distal end side connecting portion 52a can be widely flexed when the anchor portion 50 is pushed into the insertion hole 22. As a result, an angle θ between an axis of the insertion hole 22 (a longitudinal axis of the anchor portion 50) and an outer surface of each of the flexible strips 52 can be increased. This may lead to an increased insertion load (insertion resistance) in a last stage of an insertion operation of the clip. As a result, working efficiency of the clip insertion operation can be reduced.
Thus, there is a need in the art for improved clips.